为什么当我使用递归时，python中的生成器不返回任何内容

我目前正在编写一种代码，它可以通过在列表中提供我可以采用的每条路径来查找从一个机场到另一个机场的路径.机场在一本词典中，看起来是这样的: airports = {"ATL": {"lat": 33.6407, "lon": -84.4277},#and so on个 我已经实现了另一个代码，它可以计算两个位置之间的距离，称为haverine.各个航班的距离不应该超过我通过参数提供的量.更多信息在我的代码的文档字符串中.

def find_paths(airports: dict, start: str, end: str, max_distance: int, path=None):
    """
    Generates all possible paths between two airports within a given maximum distance.

    This function is a generator that yields all the paths from a starting airport to an ending         airport. Each path is constrained by a maximum distance between consecutive airports in the path. The function uses recursion and backtracking to explore all potential paths.

    Args:
    airports (dict): A dictionary where keys are airport codes and values are dictionaries containing 'lat' and 'lon' keys for latitude and longitude.
    start (str): The airport code representing the starting airport.
    end (str): The airport code representing the destination airport.
    max_distance (float): The maximum distance allowed between two consecutive airports in the path.
    path (list): The current path being explored. Defaults to an empty list.

    Yields:
    list: A list of airport codes representing a valid path from start to end within the maximum       distance constraints.
    """
    if path is None:
        path = [start]
    
    if path==end:
        yield path
        
    for i in airports:
        if i not in path:
            distance = haversine((airports[start]["lat"],airports[start]["lon"]),((airports[i]["lat"],airports[i]["lon"])))
            if distance<=max_distance:
                yield from find_paths(airports, i, end, max_distance, path+[i])
                
for i in find_paths(airports,"ATL","SIN",5000):
    print(i)

我认为，每次函数递归时，递归都会生成一个生成器.所以我试着在没有递归的情况下这样做，但我不确定该怎么做.我试着在屈服后不使用"From"，但后来我只得到了Generator对象，而不是我想要的列表.